What is a possible risk if two-factor authentication is not implemented?

When two-factor authentication (2FA) is not implemented, the security of user accounts is significantly compromised. This absence allows for a greater risk of unauthorized access to accounts. Without 2FA, attackers can gain access to user credentials through various means, such as phishing, credential theft, or brute-force attacks. The reliance on a single factor, typically just a password, increases the likelihood that unauthorized users can bypass security measures and gain access to sensitive information or assets.

The other options, while they may present valid concerns in different contexts, do not directly address the heightened security risks associated with failing to enforce two-factor authentication. For instance, while it is true that not having 2FA could potentially slow down system performance, complicate user experiences, or increase operational costs, these factors are secondary to the core risk of unauthorized account access, which is fundamentally a matter of security and data protection. The primary threat is the potential for illegitimate users to exploit accounts, making implementing robust authentication measures critical for safeguarding sensitive information.